If we both have the 5.3 liter how is the grand prix gxp making so much more power than us 5.3 liter guys?

 

IIRC the GXP has a alum 5.3?? i think... and im sure the tune is way better than ours. where you gettin 303 from? that should be the power at the crank.. and where you gettin 260 from? i think now the truck motors are at 295 crank?

 

yeah, where you get this 260 you speak of.

 

isnt that about what we put out at the wheels?

 

and i got the 303 from the pontiac website

 

stock is about 220-230 rwhp i believe and thats with GMs estimated 295hp at the flywheel.. the 303 is the Hp at the flywheel on the GXP

 

You are comparing apples to donkeys. The 303 is an SAE rating at the flywheel, the 260 is a guesstimate of how much power you are putting to the wheels. If you had one setup, you would have drivetrain loss (about 18%-22% for an auto) from the engine's output to the wheels. So take a 300 HP rated engine, it should put out about 265-275 rwhp. Sounds about right if you ask me.

 

That is a great line!! That just made my day!!